She was not only the grande dame of the Fine Arts Department during the first half of the 20th century, but also an early champion of civil rights, accepting minorities into the Fine Arts program when some other programs informally declined to do so.
During WWII, she mentored and championed the first black member of the fine arts honorary, Dolores Hale, and invited her to her home on many occasions during a time in Boulder when interracial socializing happened very rarely.
Her sketches and watercolors provide an invaluable record of the otherwise forgotten and lost ghost towns of Colorado and the West.
[5] Starting in 1928, Sibell designed sets and costumes for many theater productions on campus, including the operettas written and directed by her future husband, English professor Francis Wolle.
"[11] To the end of her life she remained active in her community and continued to keep her artistic record of America's mining past.
[13] In March 2008, St. Aidan's Episcopal Church dedicated the Muriel Sibell Wolle Gallery in her honor.